如何验证这些列？

Question

我正在使用数据库，需要验证“付款”模式下的某些列。

就像不使用信用卡付款一样，应将CreditCardNumber，CardHoldersName和CreditCardExpDate设置为NULL。 如果使用信用卡，则CreditCardExpDate值应大于PaymentDate PaymentDue可以允许为NULL，但不应大于PaymentAmount

我已经在网上搜索过，但是得到的是复杂的触发器和过程，它们并没有真正的帮助。

  create table Payment.Payments(
  Payment_ID int identity (200, 21),
  Payment_Amount money constraint chk_Payment_Amount check (Payment_Amount > 
  '0'),
  Payment_Date date, -- is to be greater than the end date which is on another table
  Credit_Card_Number int,
  Card_Holders_Name char (50),
  Credit_Card_Expiry_Date date, 
  Project_ID int Foreign Key references ProjectDetails.Projects(Project_ID),
  Payment_Due money -- should not be greater than Payment Amount but 
  can still accept null*
   );

注释显示了我当前遇到的验证问题。

我为payment_date创建了一个触发器，但是我只能在插入的日期大于当前日期时触发它，如果它小于结束日期（结束日期在另一个表上），则需要它触发

在Payment.Payments上创建触发器付款日期，以声明形式发送@@@@@ ModifiedDate日期SELECT @@@@ ModifiedDate = Payment_Date from插入的IF（@@@ ModifiedDate> getdate（））BEGIN PRINT'修改后的日期应为当前日期。 因此，无法插入。” 回滚交易结束

Answer 1

我在这里读到很多东西，但是我想这就是您想要的（注意，尽管我使用了dbo模式）：

USE Sandbox;
GO

CREATE TABLE dbo.Payments (
    Payment_ID int identity(200, 21),
    Payment_Amount money CONSTRAINT chk_Payment_Amount CHECK (Payment_Amount > '0'),
    Payment_Date date,
    Credit_Card_Number char(19), --note datatype change from int to char. See my comment below (copied from my comment)
    Card_Holders_Name varchar (50), --note I've used varchar instead. Names aren't all 50 characters long
    Credit_Card_Expiry_Date date,
    --Project_ID int FOREIGN KEY REFERENCES ProjectDetails.Projects(Project_ID) --Commented out as I don't have this table
    Payment_Due money CONSTRAINT chk_Payment_Due CHECK (Payment_Due > '0' OR Payment_Due IS NULL)
    );
GO

--Credit Card format validation
ALTER TABLE dbo.Payments ADD CONSTRAINT ck_Credit_Card CHECK (Credit_Card_Number LIKE '[0-9][0-9][0-9][0-9] [0-9][0-9][0-9][0-9] [0-9][0-9][0-9][0-9] [0-9][0-9][0-9][0-9]' OR Credit_Card_Number IS NULL);

--Add card details must be there, or none.
ALTER TABLE dbo.Payments ADD CONSTRAINT ck_Card_Details CHECK ((Credit_Card_Number IS NULL AND Card_Holders_Name IS NULL AND Credit_Card_Expiry_Date IS NULL)
                                                           OR  (Credit_Card_Number IS NOT NULL AND Card_Holders_Name IS NOT NULL AND Credit_Card_Expiry_Date IS NOT NULL))

GO
DROP TABLE dbo.Payments;

对卡号数据类型的评论：

信用卡号的数据类型int有点矛盾。 一个int的最大值为2,147,483,647，并且卡号由4组4位数字组成（即9999 9999 9999 9999 ）。 即使是数字，也远远高于int的最大值。 我建议使用char(19)并对格式进行限制。